Manufacturing of an integrated circuit has been largely driven by the need to increase the density of the integrated circuit formed in a semiconductor device. This is typically accomplished by implementing more aggressive design rules to allow larger density of the integrated circuit to be formed.
The increased density of the integrated circuit, which is combined various types of devices such as logic and radio frequency processing circuits, have generally increased the amount of noise in various circuits of the devices. Noise can be detrimental in the integrated circuit because the integrity of the signal can be compromised, which can in turn cause a loss of data or errors in logic or signal processing. Therefore, some devices in the integrated circuit are formed in a deep doped well to isolate the noise. The doped well is typically able to reduce noise between other devices in a semiconductor substrate and devices in the doped well by providing a low resistance path for the noise to travel to a ground node rather than affect devices in the doped well.
However, in manufacturing the integrated circuits, various dielectric layers are also required to be formed on the semiconductor substrate. The dielectric layers are etched to form openings for metallization layers. Plasma etching processes are commonly applied for etching these openings. Therefore, charges of these plasma etching processes can be accumulated in the deep doped well. These accumulated charges in the deep doped well could transfer and damage the devices which have conductive path to the deep doped well. It results that performance of the damaged devices would be inconsistent and uncontrollable. Accordingly, improvements in integrated circuits and fabricating methods thereof continue to be sought.